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1

Baker, Jenny. "Development and characterisation of graphene ink catalysts for use in dye sensitised solar cells." Thesis, Swansea University, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678272.

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2

Beauchamp, Damian Richard. "Molecular Engineering of Organic Photosensitizes for P-type Dye-Sensitized Solar Cells and the Immobilization of Molecular Catalyst for the Hydrogen Evolution Reaction." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1456917343.

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3

Vabbina, Phani Kiran. "Sonochemical Synthesis of Zinc Oxide Nanostructures for Sensing and Energy Harvesting." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2534.

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Semiconductor nanostructures have attracted considerable research interest due to their unique physical and chemical properties at nanoscale which open new frontiers for applications in electronics and sensing. Zinc oxide nanostructures with a wide range of applications, especially in optoelectronic devices and bio sensing, have been the focus of research over the past few decades. However ZnO nanostructures have failed to penetrate the market as they were expected to, a few years ago. The two main reasons widely recognized as bottleneck for ZnO nanostructures are (1) Synthesis technique which is fast, economical, and environmentally benign which would allow the growth on arbitrary substrates and (2) Difficulty in producing stable p-type doping. The main objective of this research work is to address these two bottlenecks and find a solution that is inexpensive, environmentally benign and CMOS compatible. To achieve this, we developed a Sonochemical method to synthesize 1D ZnO Nanorods, core-shell nanorods, 2D nanowalls and nanoflakes on arbitrary substrates which is a rapid, inexpensive, CMOS compatible and environmentally benign method and allows us to grow ZnO nanostructures on any arbitrary substrate at ambient conditions while most other popular methods used are either very slow or involve extreme conditions such as high temperatures and low pressure. A stable, reproducible p-type doping in ZnO is one of the most sought out application in the field of optoelectronics. Here in this project, we doped ZnO nanostructures using sonochemical method to achieve a stable and reproducible doping in ZnO. We have fabricated a homogeneous ZnO radial p-n junction by growing a p-type shell around an n-type core in a controlled way using the sonochemical synthesis method to realize ZnO homogeneous core-shell radial p-n junction for UV detection. ZnO has a wide range of applications from sensing to energy harvesting. In this work, we demonstrate the successful fabrication of an electrochemical immunosensor using ZnO nanoflakes to detect Cortisol and compare their performance with that of ZnO nanorods. We have explored the use of ZnO nanorods in energy harvesting in the form of Dye Sensitized Solar Cells (DSSC) and Perovskite Solar Cells.
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4

Chang, Yu-Ching, and 張鈺靖. "Nitrogen/sulfur-codoped graphene hollow nanoballs as efficient metal-free electro-catalysts for dye-sensitized solar cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/8g7k4g.

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碩士<br>國立臺灣大學<br>化學研究所<br>106<br>A huge amount of fossil fuels, such as coal, petroleum, and gas, has been consumed in order to meet the high demand of energy in the world. However, the combustion of these fossil fuels results in not only detrimentally environmental pollution, but also the rapid reduction of fossil resources on the Earth. Recently, several kinds of renewable energy, e.g., fuel cells, wind power, and solar energy, have drawn tremendous attention in academic studies and industrial applications. Among them, solar energy is the most attractive renewable energy; in particular, dye-sensitized solar cells (DSSCs) have the advantages of simple fabrication processes, low cost, flexibility, and semi-transparency. However, if a DSSC possesses low power conversion efficiency and utilizes noble metals, e.g., platinum (Pt) or ruthenium (Ru), as a counter electrode (CE), these disadvantages would hinder this DSSC from wide applications. Therefore, it is an urgent challenge to develop a noble metal-free CE with high power conversion efficiency in DSSCs. Graphene has high carrier mobility, high electrical conductivity, high mechanical strength and flexiblility. In this study, we took advantage of the unique chracteristics of graphene to fabricate high-performance DSSCs by employing different graphene-based CEs, such as graphene hollow nanoballs (GHBs), nitrogen-doped graphene hollow nanoballs (N-GHBs), sulfur-doped graphene hollow nanoballs (S-GHBs), and nitrogen/sulfur-codoped graphene hollow nanoballs (N,S-GHBs). First, we synthesized GHBs on silicon wafers (Si) or carbon cloth (CC) substrates with a chemical vapor deposition (CVD) method. A nitrogen or sulfur precursor, or both, was incorporated in the CVD rection to from N-GHBs, S-GHBs, and N,S-GHBs, respectively. Second, the as-synthesized doped GHBs were used as metal-free CEs to investigate their power conversion efficiencies in DSSCs. The highly curved GHBs could avoid the self-assembly restacking of planar graphene sheets and provide high surface area. In addition, the heteroatomic incorporation in GHBs can reduce the charge-transfer resistance and enhance the catalytic activity of GHBs. We found that pristine GHB (with ∆EP of 698 mV) and heteroatom-doped GHBs (∆EP of 530 mV for N-GHBs and ∆EP of 498 mV for S-GHBs) have different catalytic activities on the I-/I3- reduction reaction and the N,S-GHBs (∆EP of 459 mV) shows the best catalytic performance due to the synergistic effect of electronic and geometric changes. Consequently, the power conversion efficiency of a DSSC with N,S-GHBs as a CE reaches to 9.02 %, comparable to that (8.90 %) of a standard sputtered Pt CE-based cell.
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5

CHIH-HUNG, HSU, and 許志宏. "Study of Dye-Sensitized Solar Cells with Graphene Electron." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/2dgaxf.

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博士<br>國立臺北科技大學<br>光電工程系研究所<br>104<br>This work aims to improve the conversion efficiency of dye- sensitized solar cells (DSSCs) by introducing a new material, graphene, in to the DSSCs structure. Graphene is a potential material for many applications due to their high electron mobility, outstanding optical properties, and thermal, chemical, and mechanical stability. Therefore, this study changes several parameters, structures, and methods to optimize and compare with the traditional DSSCs . There are three major respects about with or without graphene, (1) the method of plating or sputtering, and the structure of (2) graphene/TiO2 and Graphene/ZnO Nanoparticles DSSCs (3) or TiO2/graphene/TiO2 in DSSCs solar cells. Finally, this research knows that the method of sputtering is much better than plating, the conversion efficiency of solar energy with graphene/TiO2 was increased from 1.62 % to 3.72 %, and the conversion efficiency with TiO2/graphene/TiO2 sandwich structure was increased from 1.38 % to 3.93 %. It means that the new material, graphene, works in enhancing the conversion efficiency of DSSCs .
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6

Lai, Yu-Cheng, and 賴禹承. "Development of dye-sensitized solar cells using graphene materials." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/12009941091035903833.

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7

Hsu, Yu-Chen, and 許瑜珍. "Graphene Oxide/ Polyaniline Nanocomposites for Dye Sensitized Solar Cells." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/86392766951057474814.

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碩士<br>國立中興大學<br>化學工程學系所<br>101<br>In this study, graphene oxide (GO)/polyaniline(PANI) nanocomposites have been used for electrode and electrolyte in dye sensitized solar cells (DSSCs).. In the fisrt part: GO/PANI nanocomposite thin film was coated on a FTO glass by in situ polymerization and and self-assembly process for counter electrode of DSSC. SEM images confirmed the formation of the composite film GO/PANI with higher surface area on the FTO coated substrate. High electro-catalytic ability and low charge transfer resistance of GO/PANI counter electrode were characterized through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The short-circuit current density (Jsc) and power-conversion efficiency (η) of the DSSC based on the GO/PANI counter electrode are about 14.94 mAcm-2 and 6.55%, which is comparable to the the cell with conventional Pt counter electrode . In the second part: the photovoltaic (PV) properties of the DSSCs were enhanced by incorporating the GO/PANI nanocomposite into the PEO gel electrolyte. The GO/PANI nanocomposite materials serve simultaneously both as the extended electron transfer materials and as catalysts for the electrochemical reduction of I3-. Because of a higher catalytic activitiy and a higher diffusion coefficient of I3- , the incorporation of GO/PANI nanocomposite into the gel electrolyte is favorable for the reduction of the charge transfer resistances of DSSC. G40P has the best catalytic activitiy as compared to those of the PANI and GO/PANI nanocomposites (G2P and G4P). Therefore, better PV efficiency (5.63%) was observed for the DSSC incorporating GO/PANI nanocomposite G40P.
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8

Tseng, Ting-Chao, and 曾亭詔. "Graphene/ZnO nanoparticle composite films for Dye-Sensitized Solar Cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/zjhpau.

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碩士<br>國立臺北科技大學<br>有機高分子研究所<br>102<br>The effects of zinc oxide doped graphene working electrode of dye-sensitized solar cells were investigated in this study. The control variables included the dispersion of graphene, the size of graphene, the amount of functional groups of grapheme, and the graphene content and thinckness of the Graphene/zinc oxide composite films. During graphene doping zinc oxide process, the graphene dipped in the mixed acid ( nitric acid : sulfuric acid = 3 : 1 ) was treated in ultrasonic bath at 60 ℃ for 2 hours. The treated graphene was cleaned with deionized water until neutral. After drying in an oven, we ground the treated graphene to powder. The powder, the treated graphene, zinc oxide nanoparticles and t-BuOH solution were mixed into the paste. The working electrode films were prepared by the doctor-blade method. The fabrication of the Graphene/zinc oxide composite films were carried out by a furnace at 150 ℃ for 1 hour. After acidification, the surface of graphene contains carboxyl and hydroxyl functional groups could improve the dispersion of graphene in a polar solvent to reduce aggregation. Besides, the functional groups of graphene linking with zinc oxide could enhance the transport of electrons. The graphene has high electron mobility due to the planar mesh structure, therefore it could effectively transmit electrons injected from the zinc oxide. The dye-sensitized solar cells with the Graphene/zinc oxide composite films were improved the short circuit current density from 6.71 mA/cm2 to 9.20 mA/cm2, and the corresponding photoelectric conversion efficiency were enhanced from 3.06 % to 3.67 %. The enhancement ratio was achieved to 20 %.
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9

Xu, Jing-Han, and 胥景涵. "Study of Graphene/TiO2 photoanode in dye-sensitized solar cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/n8h8dx.

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碩士<br>國立東華大學<br>材料科學與工程學系<br>105<br>Graphene(GR) has good photoelectric properties, including a large specific surface area, high charge-carrier mobility, high conductance, and fast electron transfer. In this thesis, different proportion of graphene is added to the TiO2 working electrodes of dye-sensitized solar cells (DSSCs). The working electrode of the studied DSSCs comprises two-layer stacking architecture. We use screen printing method to produce a light-scattering layer. The light-scattering layer is composed of the large particles TiO2-P200 nano powder and small particles of TiO2-P25 nano powder. An appropriate content of graphene in a working electrode is favorable to more uniform dispersion of TiO2 nanoparticles, leading to the increased amount of dye adsorption and absorbance of visible light. The graphene/TiO2 film forms a good electron transport path and then the time of electron transport is shortened. Furthermore, the interfacial charge transfer is accelerated and the electron lifetime is lowered. Consequently, the performance of the studied DSSC is thus enhanced.From the experimental results that GR / TiO2 working electrode with the scattering layer, get the best component conversion efficiency of 8.81 %, an open circuit of 0.74 V, a short-current density of 18.09 mA/cm2, a fill factor of 0.66.
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10

Li, Hsien-Wei, and 李顯威. "Silver/Graphene Aerogels for Anodes in Dye-Sensitized Solar Cells." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/04539673233719124639.

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碩士<br>國立雲林科技大學<br>化學工程與材料工程系<br>104<br>Recently, nano-sized TiO2 powders have been used as a working electrode for dye-sensitized solar cells ( DSSCs ) due to a higher efficiency than any other metal-oxide semiconductor. The major bottleneck is the transport of photogenerated electrons across the TiO2 nanoparticle network, which competes with the charge recombination. To suppress the recombination and improve the transport, we incorporate the three-dimensional structure of graphene aerogel into TiO2 nanostructure photoanode to form graphene aerogel bridges in DSSCs. Graphene aerogel has high specific surface area, high porosity, rapid acceptance and transfer electronic properties. So that graphene aerogel can enhance the charge transport rate to prevent the charge recombination. In addition, we incorporate the Ag/graphene aerogel into TiO2 nanostructure photoanode and hope that Ag/graphene aerogel can enhanced photocurrent of dye-sensitized solar cells. The enhancement effect is believed to be based on localized surface plasmon resonance of the Ag nanoparticles. In the present study, we used Hummer’s method and photodeposition technique to synthesize graphene coupled with Ag nanoparticles followed by self-assembly reaction to form porous structure. The morphology of the Ag/graphene aerogel characterized with HRTEM. Raman spectroscopy show that the material had surface enhance raman scattering( SERS ) property, and the signals of SERS were raised by increasing the silver loading. The part of DSSCs research was used Linear Sweep Voltammetry ( LSV ) to find that incorporation Ag/graphene aerogel could increasing photocurrent yield. Electrochemical impedance spectroscopy ( EIS ) show that it could reduce electron transit time and extend electron life time to improve cell efficiency.
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11

Wu, Wan-jhen, and 吳宛蓁. "Application of Reduced Graphene Oxide Materials for Dye-Sensitized Solar Cells." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/5qdt84.

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碩士<br>國立臺灣科技大學<br>機械工程系<br>103<br>The nanocrystalline-TiO2 film is a crucial factor of photoelectrode performances in dye-sensitized solar cells. In this study, we decreased dark current generation in the working electrode of the dye-sensitized solar cells. By adding good conductivity materials into TiO2 working electrode and thereby enhanced the efficiency of solar cells.During the preparation we added graphite and reduced graphene oxide that are well-conductive materials, since graphite and rGO can increase the short-circuit current density of DSSC therefore reduce the dark current generation, thus the light-to-electricity conversion effectively of DSSC can be effectively raised. The DSSC photoelectrodes were prepared by spin coating on ITO substrates. According to light-to-electricity conversion efficiency test, adding TiO2-Graphite, TiO2-Graphite-rGO and TiO2-rGO could increase the values of short-circuit current density (Jsc) obviously, and also improved the light-to-electricity conversion efficiency from 2.248 % to 3.572% by TiO2-Graphite, 6.409% by TiO2-rGO and 4.582% by TiO2-Graphite-rGO.
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Tien-TsaiWu and 吳添財. "Dye-sensitized solar cells containing reduced graphene oxide for enhancing performance." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/6urrvs.

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博士<br>國立成功大學<br>材料科學及工程學系<br>104<br>Dye-sensitized solar cells containing reduced graphene oxide for enhancing performance was discussed and proved its profits. Various graphene oxide (GO) samples were prepared using the Hummers method under different synthesis conditions. The obtained GO samples were evaluated for the yields and characterized for the microstructure, surface chemistry, and optical transmittance. The effects of the chemical concentrations, and the addition rates of the chemical and water on the yields and characteristics are reported. The GOs obtained consist of a few layers and exhibit good crystallinity. It was found that the yield was mainly affect by the water dropping rate as well as the NaNO3/KMnO4 ratio. Also the resulting GOs are quite similar, regardless of the synthesis conditions, except that the graphite clusters vary slightly in their sizes. GO coatings exhibit optical transmittance greater than 80% has been obtained. Furthermore, the use of reduced GO (RGO) to bridge TiO2 particles in the photoanode of dye-sensitized solar cell (DSC) for reduced electrical resistance has been investigated. The difficulty in dispersing RGO in TiO2 paste was overcome by first dispersing GO into the TiO2 paste. The GO was then reduced to RGO after the sintering of TiO2. Depending on the amount of RGO in the photoanode, the cell performance was enhanced to different degrees. A maximum increase of 11.4 % in the cell efficiency has been obtained. In particular, the inclusion of graphene has reduced the electron diffusion time by as much as 23.4%, i.e., from 4.74 to 3.63 ms and increased the electron lifetime by as much as 42.3%, i.e., from 19.58 to 27.85 ms. In order to fabricate true flexible DSC (FDSC) using Titanium (Ti) foil and indium tin oxide coated polyethylene naphthalate as the substrates for the photoanode and the counter electrode, respectively. Two types of TiO2 powders were used for making the photoanodes, namely, commercial TiO2 particles (P25) and homemade TiO2 mesoporous beads. RGO was included in selected photoanodes to improve the electrical conductivity. The fabricated cells have either a TiO2 compact layer (CL) or not. The effects of CL, RGO addition, and the use of mesoporous TiO2 beads on the cell performance are presented and discussed. We demonstrated that the optimized use of CL, RGO, and the beads improve the efficiency by as much as 154 %. On the other hand, the use of RGO connect between TiO2 particles in DSCs photoanaodes for reducing electrical resistance using heat treatment and ultraviolet(UV)-assisted reduction for GO has been investigated. Before or after the calcination, a UV-assisted reduction process was applied to remove the residuals in the photoanodes. The photoelectrodes were then employed to make DSCs. Depending on UV-assisted reduction treatment, the cell performance was enhanced to various degrees. A maximum increase of 8.24 % in the cell efficiency has been obtained. Effects of graphene addition and the UV treatment on the characteristics of the photoanodes properties and the photovoltaic performances are discussed. The resulting photoanodes were characterized using X-ray photoelectron spectroscopy (XRD), Raman microscopy, scanning electron microscopy (SEM), X-Ray Photoemission Spectroscopy (XPS), transmission electron microscopy (TEM), and UV-vis-NIR optical spectroscopy. Cell performance was evaluated using a solar simulator, incident photon to electron conversion efficiency (IPCE), and electrochemical impedance spectroscopy (EIS). These shows DSCs containing RGO were applied for enhancing performance.
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Hung, Siao-Ci, and 黃筱琪. "Gold-Modified Graphene Nanocomposites for Anodes in Dye-Sensitized Solar Cells." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/84251072526181684867.

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碩士<br>國立雲林科技大學<br>化學工程與材料工程系<br>103<br>In the structure of TiO2 nanoparticle loading dye-sensitized solar cell anode applications , boundary between the particles increase the charge recombination during transmission. To overcome this bottleneck , the TiO2 nanoparticles introduced into the graphene froming graphene grafting , to reduce the contact between the TiO2 nanoparticles , and using high conductivity of graphene to reduced charge recombination. Using gold nanoparticles can improve the dye-sensitized solar cell photocurrent , the enhancement effect is because of the localized electric fields of gold nanoparticles. This study attempts to combine graphene and gold nanoparticles to improve dye-sensitized solar cell technology. Graphene oxide was synthesized by a modified Hummers method. Au/graphene nanocomposites were prepared by chemical reducing methods. Graphene oxide and Au/graphene nanocomposites incorporation of TiO2 nanoparticles were prepared as photoanode , test dye-sensitized solar cells efficiency. Synthesis of Au/graphene nanocomposites , changing the two NaOH and NaBH4 feeding mode to get Au nanoparticle/graphene nanocomposites and Au nanowire/graphene nanocomposites. FTIR and HRXPS analysis found that the oxygen-containing functional groups of Au/graphene nanocomposites were decreased , indicating that the oxygen functional participating in the reaction. This study found that Au nanoparticle/graphene nanocomposites exhibited higher efficiency. Au nanowire/graphene nanocomposites has a shorter electron transfer time.
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Chen, Hao-Wei, and 陳豪威. "Synthesis and Application of Stacked Graphene Electrodes for Dye-Sensitized Solar Cells." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/28974209746821695250.

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碩士<br>中原大學<br>化學研究所<br>99<br>Graphene, only one single layer of carbon atoms, two-dimensional material, has good mechanical strength, physical, chemical stability and fast transfer rate of electrons. Since the price has been increased, the commonly used indium-tin oxide (ITO) conductive film exhibits its limitation in many applications, especially in soft conductive panel. Graphene is recognized to be an important alternative material for ITO conductive films. In this study, preparation of graphene thin film electrode through graphite oxide was studied. First, multi-layer stack of graphite was oxidized with sulfuric acid and potassium permanganate. The changes in oxidation time during the experiment (12h, 24h, 48h, 72h) were studied. After oxidation, the solids obtained were dried by two methods, high-temperature drying and freeze-drying, respectively. It was found that significant different water contents existed in these two solids. Heat treatment was used to reduce the GO to graphene. However, Films using high temperature drying were not stable and vulnerable to moisture and therefore become uneven, and poor electrical conductivity and low transparency. Films using freeze-drying result in a stable, good conductivity and transparent conductive films. It was found that the oxidation time 48h, and heat treatment at 650 oC could result in conductivity (≦100 Ω / □) and transparency of 75 ~ 80% at 550 nm. From the results, a standard process for a stacked graphene thin film electrodes was developed. The replacement of obtained graphene film for the conventional ITO conductive film and Pt-counter electrode was carried out. The conversion efficiencies of photo-current of DSSCs made by using the synthesized grapheme films were reported and discussed.
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Shan, Chien-Hsun, and 單建勳. "Study on Performance of Graphene as Electrode for Dye-Sensitized Solar Cells." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/3jnqgv.

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碩士<br>國立交通大學<br>顯示科技研究所<br>101<br>We have successfully transferred graphene to different positions of DSSCs, including working electrode and counter electrode. Characteristic of solar cells under illuminating by J-V curve measurement shows that graphene at working electrode has decreasing PCE due to affect by fabrication process, graphene turns out localized graphene oxide after calcined at 400°C that becomes huge resistance to hinder electron transport. On the other hand, graphene under platinum (Pt) at counter electrode has increasing PCE from 5.6% to 6.3%, Jsc increases from 15.3mA/cm2 to 17.4mA/cm2. For more investigation of composite material which combines graphene and Pt, we use it as counter electrode again and change thickness of Pt from 50nm to 200nm in DSSCs, the PCE at different thickness are promoted. From Raman spectrum measurement, D band intensity is decreased and 2D band intensity decreased with thickness of Pt increasing. Electric property measurement of the materials also demonstrate good conductivity. Graphene at counter electrode can provide more current path and more charge transfer.
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龍冠云. "Fabrication of Platinum/Platinum-Graphene Counter Electrodes of Dye-Sensitized Solar Cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/zvu5xk.

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碩士<br>國立彰化師範大學<br>機電工程學系所<br>105<br>In the thesis, the study of the processes of the platinum and platinum-graphene counter electrodes of the dye-sensitized solar cells (DSSCs) are presented. A spin coater was used for the coating of the platinum and platinum-graphene materials. The fabrication of the platinum counter electrodes, as a function of the spin speed, spin time, and sintering temperature, was studied. The influence of the concentration of the platinum-graphene materials on the characteristics of the DSSCs was investigated. The material analysis of platinum and platinum-graphene counter electrodes was conducted by the scanning electron microscope, the x-ray diffraction, and the Raman spectroscopy. The photovoltaic conversion characteristics of the DSSCs were measured. The best photovoltaic conversion characteristics were attained by a platinum-graphene concentration of 0.15M. The processes of the platinum-graphene counter electrodes have the advantage of low manufacturing costs and demonstrate excellent potential for the DSSCs.
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Wang, Chia-Feng, and 王嘉封. "TiO2/Au/graphene quantum dots composite photoanode for dye-sensitized solar cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/s3j5dw.

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碩士<br>國立中興大學<br>化學工程學系所<br>106<br>Dye-sensitized solar cells (DSSCs) based on TiO2 (pure-T), gold-loaded TiO2 (TA) and graphene quantum dots (GQDs)-loaded TA (TAGs) nanocomposites as a photoanode were fabricate. The presence of Au nanoparticles could improve the light harvesting efficiency and induces the rapid interfacial charge transfer to enhance the performance of DSSCs, but the dye adsorbed amount is decreased from 1.72×10-7 mol cm-2 to 1.67×10-7 mol cm-2. Nevertheless, the introduction of GQDs into TA composite photoanode could increase the dye adsorbed amount from 1.67×10-7 mol cm-2 to 1.87×10-7 mol cm-2 and improves the electron transport process, and thus the electron-hole pair recombination is inhibited. TAGs12 (i.e., 12 mg of GQDs) exhibits the excellent photovoltaic performance with the short-circuit current density (Jsc) of 13.90 mA cm-2 and power conversion efficiency (PCE) of 6.73%. The overall improvement in Jsc and PCE are 10.67% and 11.06%, respectively.
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Ling, Yao Hong, and 凌耀鴻. "Hydrothermal Synthesis of Graphene Sulfide-Based Composite for Dye-Sensitized Solar Cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/qrd47b.

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碩士<br>國立高雄海洋科技大學<br>微電子工程研究所<br>102<br>This study is based on hydrothermal method is applied to a prepared sulfide-based dye-sensitized solar cells counter electrode, we also by changing various process conditions, such as changing the kind of sulfide-based composite graphene, carbon black, material and adhesives, and research and explore to get the best optical characteristics of dye-sensitized solar cells. For different process conditions here by transmission electron microscopy (TEM), X-ray diffraction analyzer (X-ray Diffraction, XRD), electrochemical measuring instruments (Cyclic voltammogram, CV &, EIS), and ScienceTech150W solar battery current - voltage (IV) measurement instrument to measure and analyze the dye-sensitized photovoltaic solar cells and structural characteristics. By solar battery current - voltage (IV) measurement instrument can be learned nickel sulfide composite graphene moderate its solar energy conversion efficiency significantly enhance its efficiency increased from 1.18% to 1.91%, in some iron sulfide, a prepared Add the water, the more material, the solar energy conversion efficiency was significantly increased, the efficiency increased from 0.98% to 1.79%, more thiourea and its efficiency increased from 0.77% to 1.35%.
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Chung, Yung-Pin, and 鍾永彬. "Synthesis of highly conductive graphene materials for dye-sensitized solar cells counter electrode." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/75618204385612454020.

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碩士<br>中原大學<br>化學研究所<br>100<br>In this study, preparation of graphene thin film electrode through graphite oxide was studied. First, multi-layer stacking of graphite was oxidized using sulfuric acid and potassium permanganate for 24h. After oxidation, the solids obtained were dried by freeze-drying and coating on glass substrate, then heat treatment at 650 oC was used to reduce the GO to graphene. PEG, PEO, PVP, Terpineol were used as the binder for reforming graphene into films. It shows that the PEG-made film achieves lower resistance, higher light transmittance than those of the other three binders. The efficiency of DSSC using PEG-made grahene electrode is around 85% of those using Pt-based electrode. At the beginning of this study, the thin-film resistance of graphene electrode is about 100-30 Ω/sq, The graphene was also suffered from the electrolyte, that is the film and substrate will be unstable when liquid electrolyte was present. When the glass substrate was modified using some polyelectrolytes, the resistance of graphene films go down to 5-10 Ω/sq. In the mean time, the efficiency of DSSCs using the modified graphene film electrode can achieve 90% of those using Pt-based electrode or even better. Finally, the catalytic ability of graphene, though is no better than platinum, there edges result more amount of the catalytic sites for electron transfer. Taking these results into account, the catalytic capability of graphene can be quite compatible to that of platinum, making this material a good alternative to platinum as a counter electrode for a high performance DSSC.
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Shih, Chun-Jyun, and 施純鈞. "Investigation of graphene nanocomposite materials as counter electrodes for Dye-Sensitized Solar Cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/bgck98.

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碩士<br>國立東華大學<br>光電工程學系<br>105<br>Dye-Sensitized Solar Cells (DSSCs) have attracted much attention due to their various merits, such as relatively high efficiencies, simple device structures, easy fabrication, and low cost. These features have made DSSCs attractive for solar energy applications in the face of increasing energy and environmental challenges. A typical DSSC consists of a transparent conductive substrate, a porous thin-film photoelectrode composed of TiO2 nanoparticles, dyes, an electrolyte, and a counter electrode (CEs). Normally, platinum (Pt)is used as the CE material. However, the cost of Pt is relatively expensive. Therefore, developing a low-cost CE to replace Pt electrodes is a meaningful issue for the cost reduction of DSSCs. This study focuses on the investigation of nanocomposite materials of graphene oxide (GO) and transition metal as counter electrodes for DSSCs. There are four parts in this thesis. First, nanocomposite materials of GO and marcrocyclic Mn complex were prepared. The electrode properties and device efficiency of various weight ratio of GO and Mn macrocyclic complex were analyzed. The DSSCs fabricated with the GO/Mn (1:10) CEs achieved a power conversion efficiency of 7.47%, which was higher than that of the Pt counter electrode. Second, nanocomposite materials of GO and marcrocyclic Zn complex were prepared. The electrode properties and device efficiency were analyzed. The DSSCs fabricated with the GO/Zn (1:10) CEs achieved a power conversion efficiency of 7.78 %, which was higher than that of the Pt counter electrode. Third, nanocomposite materials of GO and marcrocyclic Co complex were prepared. The electrode properties and device efficiency were analyzed. The DSSCs fabricated with the GO/Co (1:10) CEs achieved a power conversion efficiency of 7.48 %, which was higher than that of the Pt counter electrode. Fourth, nanocomposite materials of GO and marcrocyclic Cu complex were prepared. The electrode properties and device efficiency were analyzed. The DSSCs fabricated with the GO/Cu (1:10) CEs achieved a power conversion efficiency of 7.61 %, which was higher than that of the Pt counter electrode. The results show that GO/Mn, GO/Zn, GO/Co, and GO/Cu CEs have the potential to replace Pt electrodes.
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Wang, Ting-Yi, and 王婷儀. "Electro-polymerization functionalized graphene / PEDOT-PSS composite film used in dye-sensitized solar cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/3sq66q.

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碩士<br>國立臺北科技大學<br>化學工程研究所<br>105<br>Because of high conductivity and excellent environmental stability, PEDOT-PSS is considered to a successful conductive polymer. But compared to platinum, which is more commonly used as a counter electrode of dye-sensitized solar cell, PEDOT-PSS has less oxidation-reduction ability and resulting in poor efficiency, although it can significantly reduce costs.   Therefore, we use graphene, which has good oxidation-reduction ability and excellent electrical conductivity. We functionalized graphene, and used electrochemical polymerization to form a functionalized graphene / PEDOT-PSS composite film, hoping to obtain a counter electrode which has excellent oxidation-reduction ability, and getting a higher value of light-to-electron conversion efficiency.   The functionalized graphene is identified by the Fourier transform infrared spectrometer. Scanning electron microscope and cyclic voltammetry were used to observe the surface distribution and redox potential of functionalized graphene / PEDOT-PSS composite film. Different proportions of functionalized graphene / PEDOT-PSS electrode were packaged into the dye-sensitized solar cell, and using simulated sunlight system, AC impedance test to obtain photoelectric conversion efficiency and resistance. In this experiment, the PEDOT-PSS counter electrode which added 0.01 wt% of carboxylate functionalized graphene has best efficiency of dye-sensitized solar cell, and the light-to-electron conversion efficiency was being risen from 2.58% to 3.36%. And “over-oxidation” reaction should be avoided when the electrochemical polymerization is operating, or the conductivity of PEDOT-PSS will intensely decrease.
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Shih, Yu-En, and 施友恩. "Study of Metal Nanoparticles/Graphene Nanohybrids as Counter Electrode for Dye-sensitized Solar Cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/spgq5s.

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碩士<br>國立臺灣科技大學<br>材料科學與工程系<br>106<br>In this study, we investigated the dispersibility of graphene-based material by a simple solution dispersion processing with the polyamide surfactant; utilization of nanocomposites in the counter electrode of DSSC was discussed in the same time. In the beginning, surfactant was synthesized and analysis by FT-IR, GPC, solubility. By efficiently assisting reduced graphene oxide(rGO), polyamide surfactant was used in the further experiment. Secondly, to elaborate mechanism of dispersion, different rGO were analyzed by Raman spectrum, FT-IR and element analysis. Thirdly, dye-sensitized solar cell with different oxygen-containing rGO-based counter electrode were studied. TiO2, N719, and I-/I3- were used to compose the DSSCs. The DSSC with the GO20(20% oxygen-containing) counter electrode exhibited a power conversion efficiency(η) of 5.8 %, which was comparable with DSSC with Pt electrode (7 %) under AM 1.5 illumination of 100mW cm-2. With sputter 10 nm platinum on GO20 counter electrode, the efficiency achieved 6.8 % which superior to 10 nm Pt counter electrode (3.4%). The result indicated rGO-based counter electrode need sufficient active site to catalyze tri-iodide. Finally, DSSC of FTO-free rGO/gold nanoparticles(AuNPs) were studied, replacing FTO and platinum by rGO/AuNPs film. The film with rGO/AuNPs exhibited low sheet resistance 10.3 Ω/sq, which is lower than FTO 12 Ω/sq sheet resistance. The different weight ratio of rGO/AuNPs were measured at 200/1, 20/1, 2/1. FTO-free DSSC with rGO/AuNPs 20/1 display highest efficiency at 3.66%, surpass the efficiency of FTO-free Pt electrode with 3.11% efficiency. The result provided an achievable way to enhance efficiency and cost-reduction of DSSCs.
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Wang, Yu-Chao, and 王煜詔. "Applications of Patterned FTO and Graphene Dopants to Anodes of Dye-sensitized Solar Cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/t56q27.

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碩士<br>國立暨南國際大學<br>應用材料及光電工程學系<br>102<br>Wet etching method was used to pattern FTO conductive substrates. Dye adsorption and light harvesting were enhanced, and DSSC performance was thereby improved. It has been evidenced that the optimum etching time was 240 s, which lead to an etching depth of 0.196 m and the highest device efficiency of 7.78 %. The efficiency started to decrease when etching duration was longer than 240 s. When etching time was 300 s, the device efficiency was reduced to only 5.84 %, which was even lower than that of the device with non-patterned FTO electrode. This could be ascribed to the larger sheet resistance caused by a deeper etching. The DSSC performance was greatly reduced when the influence of increased dye adsorption could not compete with the impact brought by abrupt increase of sheet resistance. Graphene oxide was successfully reduced to graphene using autoclave, and this has been demonstrated by the results of Raman, XRD and XPS analyses. Graphene was doped into TiO2 electrode, which was applied to DSSC to improve device performance. It was discovered that appropriate graphene doping could enhance dye adsorption and visible absorption. The optimum ratio of graphene doping in TiO2 was 0.005: 1. Moreover, it has also been demonstrated that three-layer graphene-doped TiO2 covered on FTO conductive substrates would be better than two- or one-layer graphene-doped TiO2 and could achieve an optimum device efficiency of 2.56 %. Graphene was favorable for dispersion of TiO2 nanoparticles and reduction of electrolyte by the dye, leading to improved electron transfer at the interface and decreased probability of electron-hole recombination. The path and time of electron transport were thereby reduced. Nevertheless, excessive graphene doping caused non-uniform dispersion of TiO2 nanoparticles and reduced specific surface area and amount of dye adsorption. This could result in smaller photocurrent density and lower DSSC performance. In this study, the most optimized ratio of graphene doping in TiO2 has been found out.
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Li, Dong-Lin, and 李東霖. "Preparation of Functionalized Graphene / PEDOT-PSS Composite Film and Application to Dye-sensitized Solar Cells." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/xgy2mc.

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碩士<br>國立臺北科技大學<br>化學工程研究所<br>101<br>In this study we improve the DSSC of battery. There are many dye-sensitized solar cells using platinum as counter electrode. But the platinum is too expensive that we hope to use the low cost conducting polymer as counter electrode materials. Because the PEDOT-PSS of conductive polymer that oxidation reduction is bad, we add grapheme which not only has a good oxidation-reduction ability but also the conductivity is high. We use the simple process to manufacture the dye-sensitized solar cells which are able to use in large-scale industrial manufacturing. Matrix includes ITO glass as well as flexible element(ITO-PET). we use X-ray Diffraction, Scanning Electron Microscopy, Energy Dispersive Spectrometer, UV–visible to identify the property of optical, chemistry, film surface as we manufacture dye-sensitized solar cell.Batteries with different ratios of the graphene on the electrode package use the system of simulated sunlight, EIS, to get photoelectric conversion efficiency and the resistor of the cell. The ITO glass which is added 0.1g ofgrapheme has the best efficiency , and the photoelectric conversion efficiency is 3.78%. Regarding the flexible element, the one with 0.5g of grapheme has the best efficiency, the photoelectric conversion efficiency is 0.3552%. Efficiency in flexible element above to be strengthened.
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Shiu, Shiao-Long, and 許曉壟. "Investigation of Graphene-Based Gel-State Electrolytes and Counter Electrodes for Dye-Sensitized Solar Cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/8pvxgv.

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碩士<br>國立東華大學<br>光電工程學系<br>106<br>Dye-Sensitized Solar Cells (DSSCs) have attracted much attention due to their various merits, such as relatively high efficiencies, simple device structures, easy fabrication, and low cost. These features have made DSSCs attractive for solar energy applications in the face of increasing energy and environmental challenges. However, the problems of electrolyte's sealing, corrosion, thus lack of stability and the cost of Pt isrelatively expensive limit the commercialization of DSSCs. There are three parts in this study. First, we added the graphene, the lithium bis(trifluoromethanesulphonyl)imide, and camphorsulfonic acid into PMMA gel-based electrolytes, and the properties of the DSSCs were analyzed by J–V, IPCE, electrochemical impedance, and stability measurements. The highest power conversion efficiency of 8.46% was recorded for quasi-solid-state DSSCs with 0.05M Li bis, 0.05M CAS and 1.3mg/ml graphene . Second, the TiO2 nanoparticles and the graphene are employed to solidify an acetonitrile-based liquid electrolyte for DSSCs, and the properties of the DSSCs were analyzed by J–V, IPCE, electrochemical impedance, and stability measurements. The highest power conversion efficiency of 8.87% was recorded for quasi-solid-state DSSCs with 10.0 wt% TiO2 nanoparticles and 1.3mg/ml graphene as the gelator. Third, nanocomposite materials of GO and marcrocyclic Yb complex were prepared. The electrode properties and device efficiency were analyzed. The DSSCs fabricated with the rGO/Yb (1:10) CE exhibited a power conversion efficiency of 7.9%, which was higher than that of the Pt counter electrode.
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Zhang, Zhi-Jia, and 張志嘉. "Electrophoretic Deposition of Graphene-Based Thin Films and its Application in Dye-Sensitized Solar Cells." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/46276798348586535989.

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碩士<br>大葉大學<br>工業工程與管理學系<br>103<br>This study can be divided into two parts. In the first part, In spin coating method graphene suspension was uniformly dispersed onto Corning 1737 glass, Preparation of the conductive film: Then by electrophoresis deposition method, compared the graphene deposited on ITO glass substrate. The catalytic through modified Hummers method, So more efficiently dispersed graphene in solution, The four-point probe in electrophoretic deposition of graphene way better than the effect of the spin coating method;Then using Hall Effect analyzed, The results show that the deposition parameters 10v60s best carrier concentration of 4.34 (× 1017cm-3). The second part is the electrophoretic deposition of graphene deposited on ITO substrate. As the dye-sensitized solar cell electrode, then replaces the platinum electrode, by controlling the voltage and time of the preparation to corresponding electrode. The working electrode layer is three TiO2, Its photoelectric conversion efficiency measured DSSC, The photoelectric conversion efficiency of DSSC measurements AM1.5 simulated solar light irradiated to the element results: 10v-60s deposition of electrodes is better, η% with increasing voltage and time, its efficiency will be a slight increase.
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Lin, Yi-Jhen, and 林伊眞. "Preparation of Graphene Quantum Dots and Their Application for Photoanodes of Dye-Sensitized Solar Cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/19333003459471504475.

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碩士<br>國立高雄應用科技大學<br>化學工程與材料工程系博碩士班<br>105<br>Graphene has been widely studied since it has been studied by good mechanical stress, high specific surface area, electron transport efficiency and biocompatibility. When we have made graphene in chemical or physical way When it is reduced in size, it will change its nature due to quantum confinement and marginal effects. When its energy level is regulated to the proper range, it may release fluorescence, which is regarded as Graphene Quantum Dots). In addition to the various advantages of graphene as described above, the graphene quantum dots of different sizes were prepared by the different reaction temperature at the reaction time, and the synthesized ferrite quantum dots were mixed with the titanium dioxide nanometer Tube applied to the dye-sensitized solar cell anode. In this study, we investigated the effect of graphene quantum dots with different particle sizes on the photoanitrogenation of dye-sensitized solar cells, and discussed the effect of dye-sensitized solar cells. In this paper, a simple, low - cost and high - yield graphene quantum dots were prepared. The grained graphene was prepared by modified Hummer 's method, the pH value was adjusted to alkaline, and the graphene quantum dots were prepared by hydrothermal method. According to the identification of XRD, SEM, TEM and AFM, the particle size of the graphene quantum dots is 1-3 nm and the number of layers is 1-2 layers. The graphene quantum dots of small particles are easy to enter into the matrix Titanium dioxide nanotubes, is conducive to the working electrode photoelectric conversion efficiency. In terms of components, the photodiode of dye-sensitized solar cells with different sizes of graphene quantum dots and arrayed titania nanotubes with no graphene quantum dots were compared. From the experimental results show that the use of graphene quantum dots to help improve the dye-sensitized solar cell photoelectric conversion efficiency, , the best can be achieved 2.13 %.
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Chen, Szu-Chien, and 陳思蒨. "Applications of PANI and PEDOT as Cathodic Catalysts for Pt-free Dye-Sensitized Solar Cells." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/51424854601972144035.

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碩士<br>國立中央大學<br>化學研究所<br>99<br>Dye-Sensitized Solar Cells (DSSCs) are attractive the third generation thin film solar cells due to their low cost, light weight, colorful, fabricated easily and flexible. Generally, platinum is employed as a catalyst for the cathode in DSSC to catalyze the reduction reaction (I3- to 3I-) of the electrolyte. However, platinum is one of the most expensive materials on the earth. The preparation of Pt counter electrode at high temperature also increases the cost and difficulty in fabricating large-size device. Therefore, extensive studies have been carried out for developing other cheaper materials to replace Pt in DSSC. In this study, we investigated the performance of DSSCs using polyaniline (PANI) or poly(3,4-ethylenedioxythiophene) (PEDOT) as a catalyst on the counter electrode. We found that HFIP (Hexafluoroisopropanol) is a very good solvent for PANI and PEDOT powder. PANI and PEDOT counter electrode with large surface area and good conductivity can be made from PANI/HFIP and PEDOT/HFIP solution simply by spin coating at room pemperature, and the heating process is unnecessary. DSSC uses PANI/ FTO as a counter electrode exhibits an efficiency of 7.77 % with CYC-B11 as a sensitizer ( Pt:8.83 % ). Nevertheless, the efficiency of DSSC used PANI-SO4-HFIP CE (made from the H2SO4-Doped PANI/HFIP solution by spin coating the film on FTO) as counter elctrode achieves the highest efficiency of 8.76 %,which is comparable to that (8.83 %) of Pt-based DSSC under the same fabrication and measurement conditions. Furthermore, dispersing of PEDOT powder in HFIP was also used to prepare PEDOT counter electrode (PEDOT CE) by spin coating. The efficiency of PEDOT CE-based DSSC with CYC-B11 as sensitizer is 8.98 % ( Pt:8.74 % ). The results proved that conjugated polymers are good materials for replacing Pt as a counter electrode catalyst for DSSC.
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Hsu, Chih-hsuan, and 許芷瑄. "Application of Multi-wall Carbon Nanotube and Graphene modified TiO2 nanoparticle to Dye-sensitized Solar Cells." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/xjbtsk.

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碩士<br>國立臺北科技大學<br>化學工程研究所<br>99<br>The nanocrystalline-TiO2 film is a crucial factor of photoelectrode performances in dye-sensitized solar cell. In this study, we decreased dark current generation in the working electrode of the dye-sensitized solar cell. By adding good conductivity materials into TiO2 working electrode and thereby enhanced the efficiency and stability of solar cells.We used sol-gel method to prepare nanoscale titanium dioxide (TiO2). During the preparation we added multi-walled carbon nanotubes and graphene that are well-conductive materials, since CNT and graphene can increase the short-circuit current density of DSSC therefore reduce the dark current generation, thus the light-to-electricity conversion effectively of DSSC can be effectively raised. We used TiO2-CNTs, TiO2 nanoparticles coated on the surface of the muti-wall carbon nanotubes, and TiO2-Graphene composite nanopowders, the graphene sheets covered heavily with TiO2 layer, as the photoelectrode materials for dye-sensitized solar cells (DSSC). The DSSC photoelectrodes were prepared by spin coating on transparent conductive Indium tin oxide (ITO) substrates. According to light-to-electricity conversion efficiency test, adding TiO2-CNTs and TiO2-Graphenes nano composite powders could increase the values of short-circuit current density (Isc) obviously, and also improved the light-to-electricity conversion efficiency from 3.5928 % to 5.242% by TiO2-CNTs and 5.619% by TiO2-Graphenes.
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WANG, WUN-SHIUAN, and 王文璇. "Reduced Graphene Oxide/Macrocyclic Metal Complex Hybrid Materials as Counter Electrodes for Dye-Sensitized Solar Cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/vs7npd.

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碩士<br>輔仁大學<br>化學系<br>105<br>Dye-sensitized solar cells (DSSCs) have the advantages of simple process, high efficiency, and low cost. DSSCs have been investigated extensively due to their various features and merits for applications in renewable energy. A typical DSSC consists of a transparent conductive substrate, TiO2 nanoparticles, dyes, an electrolyte, and a platinum (Pt) counter electrode (CE). However, Pt is a rare and expensive metal element and may limit the DSSC applications. As such, replacing the expensive Pt with other materials having the required electrochemical properties for the counter electrode will be much welcome. The RGO/metal CEs exhibited efficient electrocatalytic capability because catalytic matel particles were uniformly distributed on the surface of RGO. The results indicate that a DSSC with a GO/metal CE can exhibit an efficiency comparable to that of a Pt CE DSSC and can therefore replace conventional Pt CE DSSCs to lower the cost of solar cells. There are four parts in this thesis. First, reduced graphene oxide (RGO)/macrocyclic iron (Fe) complex hybrid materials were synthesized. This material was successfully used in counter electrodes (CEs) of dye-sensitized solar cells. The electrode properties and device efficiency based on the GO/Fe were analyzed. Results showed that DSSCs based on GO/Fe(1:10) CEs achieved a conversion efficiency of 6.75%. Second, reduced graphene oxide/macrocyclic cobalt (Co) complex hybrid materials were synthesized. This material was successfully used in CEs of DSSC. The electrode properties and device efficiency based on the GO/Co were analyzed. Results showed that DSSCs based on GO/Co (1:10) CEs achieved a conversion efficiency of 7.48%. Third, reduced graphene oxide/macrocyclic copper (Cu) complex hybrid materials were synthesized. This material was successfully used in CEs of DSSC. The electrode properties and device efficiency based on the GO/Cu were analyzed. Results showed that DSSCs based on GO/Cu(1:10) CEs achieved a conversion efficiency of 7.61%. Finally, reduced graphene oxide/macrocyclic zinc (Zn) complex hybrid materials were synthesized. This material was successfully used in CEs of DSSC. The electrode properties and device efficiency based on the GO/Zn were analyzed. Results showed that DSSCs based on GO/Zn (1:10) CEs achieved a conversion efficiency of 7.78%.
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Wu, Hsin-Hui, and 吳忻蕙. "Low-Temperature Fabrication of Platinum Nanostructures and Novel Platinum/Graphene Nanocomposites for Dye-Sensitized Solar Cells." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/92699074998954468881.

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碩士<br>國立交通大學<br>應用化學系分子科學碩博士班<br>100<br>Polyol synthesis is a successful method to generate metal nanostructures with well defined and controllable shapes. Here we report the fabrication of Pt nanostructures as transparent counter electrode (CE) for dye-sensitized solar cells (DSSC) via a dip-coating process suitable for flexible devices. A self-assembled monolayer (SAM) of Pt nanostructures was fabricated by linking Pt nanoparticles with thio functionalized transparent conducting oxide (TCO) substrate. Scanning electron microscope (SEM) top-view images show the Pt nanoparticles homogeneously distributed on the surface of a fluorine doped tin oxide (FTO) conductive glass. Ttransmission electron microscopic (TEM) cross-section images reveal that the Pt nanopaticles are highly crystalline and self-organized on the substrate with a uniform size of 2 nm in diameter. The DSSC device made of SAM CE and optimized TiO2 photoanode attained an overall power conversion efficiency 9.2% on indium tin oxide (ITO) substrate, which is slightly higher than the device with a conventional thermal cluster Pt (TCP-Pt) CE on FTO substrate (9.1%) ;the device made of SAM CE on FTO substrate gives the efficiency 9.0%. As second part of this thesis, a novel structure of Pt/Graphene nano-composite was developed as CE materials for DSSC applications. Using cyclic electro-deposition (CED) approach previously developed in this laboratory, Pt nanostructures were deposited uniformly on a graphene thin film, dispersed on the surface of FTO substrate. Post-treatments of graphene nanosheets to increase the amount of oxygen-containing functional groups and the defect sites were performed to improve the catalytic activity. In our study, the device incorporating Pt-grafted graphene CE showed a power conversion efficiency 8.0%, which is slightly higher than that of a device made of conventional TCP-Pt CE (7.9%), due to an improvement of FF. The CEs made of Pt/Graphene composite are superior to other electrodes that consist solely of graphene or Pt films. Based on the results obtained from the impedance spectral measurements, the charge transfer resistance of Pt/Graphene CE is 1.8 Ω, which is smaller than that of TCP-Pt CE (3.5Ω) and that of graphene CE (23KΩ). Our results indicate that the Pt/Graphene composite materials have excellent electro-catalytic performance, perfectly suitable for use as CE for DSSC.
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張文豪. "Characterization of MoS2–graphene and MoS2–TiO2 composite films as counter electrodes in dye-sensitized solar cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/8sf6h3.

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碩士<br>國立彰化師範大學<br>光電科技研究所<br>102<br>The effect of annealing on the optoelectronic and electrical properties of MoS2 films was examined. The MoS2 film was annealed in the ambient nitrogen and vacuum, respectively. The crystallinity can be enhanced while annealing in vacuum. However, annealing in pure nitrogen ambient could make some of nitrogen incorporation into MoS2, resulting in the degraded crystallinity. A link between the electrical property, crystallinity and annealing temperature of the MoS2 film was established. In addition, the MoS2-graphene and MoS2-TiO2 composite films were characterized as the counter electrodes for Pt-free dye-sensitized solar cells (DSSCs). It is shown that the MoS2-graphene (MoS2-TiO2) counter electrode has a noticeable effect on the power conversion efficiency of DSSCs. A direct link between the power conversion efficiency of DSSCs and the transfer resistance of the MoS2-graphene (MoS2-TiO2) counter electrode was established.
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Chen, Po-Hao, and 陳泊豪. "Study of TiO2/graphene composite compact layer on improvement in the performance of dye-sensitized solar cells." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/79096115723273446542.

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碩士<br>國立臺灣海洋大學<br>光電科學研究所<br>103<br>The TiO2/graphene nanosheets composite compact layer (CLs) was used to improve the performance of dye-sensitized solar cells (DSSCs). The experimental results revealed that DSSCs with TiO2/graphene composite CLs had superior performance to that of DSSCs with only TiO2 CLs or without TiO2 CLs. In addition, the DSSCs with TiO2/graphene layer were found to be extensively improved in the light-to-electricity conversion efficiency, short-circuit current, open-circuit voltage and fill factor with the increments of 40%, 7%, 4% and 27%, respectively compared to that of DSSCs without CLs. It was found that the TiO2/graphene CLs can act as a blocking layer and an auxiliary transparent conducting oxide layer for the DSSCs from the observations of decreased dark current and increased photovoltage transient. These improvements can be attributed to the effective suppression of the charge recombination from transparent conduction oxides to the electrolyte, and the improved carrier transport properties of the TiO2/graphene CLs.
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Chang, Che Wei, and 張哲維. "A hybrid nanocomposite of molybdenum disulfide and reduced graphene oxide as counter electrode for dye-sensitized solar cells." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/4a64yt.

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碩士<br>國立清華大學<br>工程與系統科學系<br>103<br>In this study, the molybdenum disulfide/ nitrogen doped graphene oxide nanocomposite (MoS2/nGO) was synthesized with nitrogen doped reduced graphene oxide (nGO) by hydrothermal synthesis method and molybdenum disulfide (MoS2) by thermal reduce method. This hybrid nanocomposite coated on fluorine doped tin oxide (FTO) glass as a platinum-free counter electrode (CE). The characteristics of MoS2/nGO were investigated by high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopy. The electrochemical property of MoS2/nGO was characterized by cyclic voltammetry (CV), electrochemical impedance spectra (EIS) and Tafel-polarization measurement. This MoS2/nGO CE exhibited well photovoltaic conversion efficiency (PCE = 5.95 %). Compared with the conventional Platinum, the MoS2/nGO CE was up to 93.4% of using conventional Pt CE (PCE = 6.43 %). As a result of the MoS2/nGO nanocomposite could provide an alternative selection to replace the noble platinum as CE for DSSCs.
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HSU, YU-CHIEN, and 徐語謙. "Poly(o-methoxyaniline) and its Graphene-based Composite Materials Fabricated as Counter Electrodes of Dye Sensitized Solar Cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/ub34me.

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碩士<br>輔仁大學<br>化學系<br>105<br>Dye-sensitized solar cells (DSSCs) have the advantages of simple process, high efficiency, and low cost. DSSCs have been investigated extensively due to their various features and merits for applications in renewable energy. However, Pt is an expensive metal element and may limit the DSSC applications.As such, replacing the expensive Pt with other materials having the required electrochemical properties for the counter electrode will be much welcome. There are two parts in this thesis. First, a conductive polymer poly(o-methoxyaniline) (POMA) doped with an organic acid, 1S-(+)-camphorsulfonic acid (CSA), was used to fabricate counter electrodes for dye-sensitized solar cells, and the effects of POMA doped with various weight ratios of CSA on the efficiency of DSSCs were investigated. The electrodes of POMA-CSA exhibited with increased surface roughness, increased crystallinity, and decreased impedance. The characteristics of DSSCs based on POMA-CSA electrodes were analyzed using J-V, IPCE, and EIS measurements. The experimental results reveal that the POMA-CSA(16%) electrodes exhibited the optimal electrode characteristics. The DSSC based on POMA-CSA(16%) CE reached an efficiency of 8.76%, which was higher than that of DSSCs with platinum CE. Second, Covalent bond–grafted soluble poly(o-methoxyaniline)- –functional graphene oxide (POMA-FGO) nanocomposite materials were prepared and doped with 1S-(+)-camphorsulfonic acid as counter electrodes for realising dye-sensitised solar cells. DSSCs with the POMA-FGO and POMA-FGO-CSA CEs exhibited substantially reduced interfacial impedance, which may be attributed to dual improvement from the well-dispersed FGO and the doping effect of CSA. Therefore, the efficiency levels of the DSSCs fabricated with the POMA-FGO CEs were higher than those of the DSSCs fabricated with the POMA CEs. When CSA was doped with the CEs, the efficiency of the DSSC was further enhanced. In particular, the efficiency of a DSSC based on the POMA-FGO (0.5%)-CSA (16%) CEs reached 8.81%, which was higher than that of a DSSC with a conventional platinum electrode. Therefore, POMA-FGO-CSA–based CEs can serve as a potential alternative to expensive platinum CEs.
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CHI, WEN-FENG, and 紀文峯. "Graphene/ Macrocyclic Nickel Complex Hybrid Materials and its Application for the Counter Electrode of Dye-Sensitized Solar Cells." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/19978866400654924487.

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碩士<br>輔仁大學<br>化學系<br>103<br>Dye-sensitized solar cells (DSSCs) have obtained exciting progress in improving energy conversion efficiency and reducing material cost in recent years. It was found that many kinds of inorganic materials have promising potential to replace platinum (Pt) as counter electrode (CE) materials for DSSCs. In this study, we developed novel graphene/ macrocyclic nickel complex hybrid materials for the CE of DSSCs. The properties of our DSSCs were compared with the traditional Pt CE. Due to the low cost and high performance of our CE materials, there is potential for replacing the expensive Pt CE material. Using different ratios of graphene oxide and macrocyclic nickel complexes, we prepared various hybrid materials. The as-prepared hybrid materials were characterized by FTIR, XRD, XPS, SEM and TEM. As a result, nickel macrocyclic complexes reacted with graphene oxide can effectively guiding the metal complexes distributed uniformly on the surface of graphene. The redox properties of metallic complexes supporting with the high specific surface area and high conductivity of graphene are expecting to increase the electrocatalytically effects in reversibility and electro-activity for the iodine based electrolytes of DSSCs. The properties of devices were analyzed by CV, IPCE, EIS and J-V curve. As a result, the CE fabricated with the GO/Ni(1:3) hybrid material had a better redox behavior for I3-; which IPCE reached 90%, and exhibited the lowest impedance. Comparison with the same devices structure, the device efficiency based on GO/Ni(1:3) CE reaching for 8.3%, which is better than the Pt based CE with efficiency for 7.96%. The results prove that using the materials of nickel macrocyclic complex hybrid with graphene could successfully apply for the CEs of DSSCs.
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Huang, Ying-Chun, and 黃盈竣. "Interface functionalization of photoelectrodes by electrophoretic deposition of graphene quantum dots for high performance dye-sensitized solar cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/69897848922958358126.

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碩士<br>國立中興大學<br>化學工程學系所<br>105<br>In the dye-sensitized solar cells (DSSCs), the performance of DSSCs is extremely related to photoelectrodes. Interface of fluorinated-tin oxide (FTO)/TiO2, TiO2/TiO2, and TiO2/electrolyte in the DSSCs directly influence the power conversion efficiency (PCE). In this study, graphene quantum dots (GQDs) synthesized by pyrolyzing citric acid are introduced to modify the interface between FTO and TiO2 so as to suppress charge recombination. The surface morphology of GQDs-decorated FTO is demonstrate by SEM and AFM. In addition, electrochemical impedance spectra (EIS), itensity modulated photocurrent spectroscopy (IMPS) and intensity modulated photovoltage spectroscopy (IMVS) are applied to survey the charge recombination. The final PCE of DCCS is enhanced from 8.34% to 9.35%, accompanied by the increase of short-circuit photocurrent density, and overall improvement in PCE is 12.1%. The suppression of charge recombination and increase of charge transfer rate are both evidences of an improvement in PCE.
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38

Chiang, Peng-Wei, and 江朋威. "Effects of different catalysts on the growth of ZnO nanorods for the application of dye-sensitized solar cells." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/28130207439968171883.

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碩士<br>國立中興大學<br>光電工程研究所<br>99<br>The analysis is mainly aimed at transforming Zno nanorods to array on the ITO substrate by Chemical Bath Deposition (CBD), and utilizing for the electrode pole of Dye-sensitized solar cells (DSSC). This investigation would help us in evaluating how three different kinds of catalysts (NaOH, NH4OH and HMT) and their respective reaction time (3, 6 and 9 hours) have an influence on the composition of Zno nanorods, superficial micro structure, optical and photo electricity attribution.The nanorods are grown with three kinds of catalysts is at wurtzite structure composition category, and to be provided with the characteristic of C axis (002) orientation. The nanorods grown with HMT has greater growth rate and aspect ratio, whilst the reaction time increases, the length of nanorods goes up correspondingly. According to PL analysis, the intensity of ultraviolet of Zno nanorods escalates with the rising reaction time. It was observed that as the reaction time increases, the crystalline of Zno nanorods gets stronger, which further results in an effect of enhanced intensity of ultraviolet.In addition it was noted that, the lattice structure of nanorods transformed with NaOH has the worst outcome. Furthermore, it also runs short of oxygen defects at most. With view point of DSSC, the Zno nanorods transformed with HMT has better efficiency on converting photoelectricity, and accounts for 0.644 percent. Due to its greater aspect ratio, and better dye attachment, the current and converted efficiency possesses better performance. However, the Voc and F.F. does not rise up with respect to the reaction time which concludes that the loop resistance does not increase with the nanorods aspect ratio accordingly. Therefore, it could be concluded that the nanorods has greater electricity attribution.
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39

WANG, JHIH-YI, and 王芝貽. "The Study of the Photo-efficiency of Dye-sensitized Solar Cells by the Modification of Working Electrodes with Graphene." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/z9tnw2.

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碩士<br>國立臺北科技大學<br>化學工程與生物科技系化學工程碩士班<br>107<br>In this study, the working electrodes of dye-sensitized solar cells were prepared by screen printing method, and the purpose of this study is to discuss the effect of dye- sensitized solar cells by the modification of working electrodes with different materials and scattering layers. We took X-ray diffraction analyzer (XRD), Raman spectroscopy (Raman) and field emission scanning electron microscopy (FE-SEM) for analysis and identification of the materials. The amount of dye adsorption was measured by UV/Vis spectrometer, and the performance was analyzed by photoelectric conversion efficiency analysis (I-V), incident photon-to-electron conversion efficiency (IPCE) and electrochemical impedance spectroscopy (EIS). Based on the data of I-V, we could know that graphene played the role of the path of electron transmission, reducing the back reaction and increasing the amount of dye absorption, which increases the efficiency of graphene from 6.242% to 6.725%. Although the addition of appropriate amount of polyimide made the short circuit current decrease slightly, the open circuit voltage, FF value and efficiency were obviously improved. Because the missing current was reduced, the efficiency can reach to 7.086%. At last, the sample with the appropriate amount of graphene and polyimide achieved the maximum efficiency of 8.170%. From the results of EIS, it showed that the R2 impedance significantly reduced for adding graphene and polyimide, indicating that graphene played the role of the electron transport path to make electrons more easily transportable. Besides, polyimide could reduce the back reaction. Adding a scattering layer could also reduce the R2 impedance. It was speculated that the effective use of photons increased the short circuit current density and the excitation electron transition to the working electrode conduction band to facilitate electron transport. Finally, the best performance of the sample was achieved by mixing the appropriate amount of graphene and polyimide.
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40

Lin, Hsiao-Li, and 林筱莉. "Processing and Performance of Polyaniline/Multi-walled Carbon Nanotubes / Graphene Composites as Counter Electrodes for Dye-sensitized Solar Cells." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/42772526204201428114.

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碩士<br>國立臺灣大學<br>高分子科學與工程學研究所<br>102<br>This paper is mainly concerned with the replacement of platinum with polyaniline (PANi), graphene and multi-walled carbon nanotube (MWCNT) composite films used as a catalysis layer in counter electrode of dye-sensitized solar cells (DSSC). First, we used aniline sulfate solution as an efficient dispersing agent to debundle MWCNTs and to avoid graphenes aggregated. The composite films were grown on fluorine-doped tin oxide (FTO) and glass substrates by using electro-chemical deposition and chemical/electro-chemical deposition respectively. From the results of four-point probe and thermo-gravimetric analysis, the surface resistance and the weight loss percentage of the films were decreased with the addition of graphenes and MWCNTs. Accordingly, the PANi/Graphene/MWCNTs composite films were successfully fabricated by electro-chemical deposition and chemical/electro-chemical deposition. In the first part of this research, the PANi film were grown on the FTO-coated glass as counter electrodes of DSSCs by using electro-chemical deposition. The power conversion efficiency of as-fabricated DSSC was 5.55±0.05 % .When adding the proper amount of graphenes and MWCNTs (aniline/graphene=1/0.0045;aniline/MWCNTs=1/0.0045 ) , the power conversion efficiency were raised to 7.29±0.08% and 7.21±0.08% . The highest power conversion efficiency was 7.67±0.05%, when the weight ratio of aniline/graphene/MWCNT was 1/0.0030/0.0045. In addition , the addition of graphene and MWCNTs could enhance the Jsc of DSSC from 15.48 to 18.21 mA/cm2. In the second part of this research, the PANi film was grown on the glass slide as a counter electrode of DSSC by using chemical/electro-chemical deposition. The highest power conversion efficiency of as-fabricated DSSC was 0.58±0.02%. When adding the proper amount of graphenes and MWCNTs (aniline/graphene=1/0.0060;aniline/graphene=1/0.0060) , the power conversion efficiency were raised to 2.04±0.08% and 2.03±0.07%. The highest power conversion efficiency was 3.58±0.06%, when the weight ratio of aniline/graphene/MWCNTs was 1/0.0045/0.0060. In addition , the addition of graphene and MWCNTs could enhance the Jsc of DSSC from 3.64±0.06 to 9.38±0.07 mA/cm2. From the result of cyclic voltammetry (CV) analysis, the PANi/Graphene, PANi/MWCNTs, and PANi/Graphene/MWCNTs composite films compared to neat PANi have higher catalysis of converting tri-iodide (I3-) to iodide (I-) due to their higher conductivity and higher redox current density. The increase of redox current density resulted in higher Jsc, higher power conversion efficiency, and better charge collection efficiency of DSSCs. In addition, the open-circuit voltage of DSSCs was higher with the PANi/Graphene/MWCNTs counter electrode because of the higher reduction potential for I-/ I3- redox couples.
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41

Chou, Peng-Yi, and 周朋毅. "A Study on Organic/Inorganic Graphene Nanohybrid Materials and Their Applications in Manipulating Superhydrophobic Surface and Dye-Sensitized Solar Cells." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/27522h.

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碩士<br>國立臺灣科技大學<br>材料科學與工程系<br>104<br>Nano-manipulation is considered to be very important foundation research in nanotechnology. With the development of technology, the products have become the trend of miniaturization of materials that size from microns to nanometers. Therefore, the dispersion techniques urgently need to promote in order to approach the current demand. In this thesis, there are two parts describing the polymeric dispersants to achieve the nanohybrids of graphene platelets/-particle/-tubes nanomaterials or complexes will be prepared via the geometric shape in-homogeneity factor dispersing method and the corresponding functions including hydrophilic/hydrophobic dispersing properties. According to their functions, it could be searched possible applications, such as superhydrophobic surface and electrodes in dye-sensitized solar cells. The content of study is described as follow: In this study, the first part we report the micro-/nano- manipulation of highly surface roughness by star-shaped highly hydrophobic polymeric dispersants finely stabilized the nanohybrids of carbon black (CB), carbon nanotubes (CNTs), and reduced graphene oxide (rGO). The star-shaped organic dispersant, namely a polyisobutylene-imide copolymer (PIB-imide), was synthesized via amidation and imidation reactions of polyisobutylene-g-succinic anhydride (PIB-SA) and poly(oxypropylene)-triamine (Jeffamine T403) of approximately 440 average molecular weight (Mw). The dispersion mechanism between the carbon materials and the PIB-imide through non-covalent interactions such as hydrophobic effect. Furthermore, the hybrid films exhibiting a highly water-droplet contact angle of 158o and the sliding angle of 2o. Adding PMMA enhance the mechanism of micro/nanostructure also exhibiting a highly water-droplet CA of 152o and SA of 3o. The organic/inorganic nanohybrids are proven to be a convenient method for mimicking Lotus leaf surfaces and potential useful for manufacturing superhydrophobic coating. The second part choosing of reduced-grapheme oxide. Graphene has excellent electrical conductivity and catalytic properties. Adding an organic dispersant to help graphene dispersed and fabrication grapheme-carbon nanotubes and grapheme-carbon black composite electrode optimization of counter electrodes replace expensive platinum electrodes in dye-sensitized solar cells.
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42

WANG, FA-SHAN, and 王法善. "(1)Preparation and Property Studies of Hydrogenated Epoxy/Graphene Nanocomposites(2)Graphene/Chromium Complex Hybrid Materials for the Counter Electrode of Dye Sensitized Solar Cells." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/7nz83x.

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碩士<br>輔仁大學<br>化學系<br>107<br>In the first part of research, we prepared hydrogenated diglycidyl ether of bisphenol A (HDGEBA)/graphene nanocomposite materials which incorporated with graphene oxide (GO) or with funtionalized graphene oxide (FGO) by the In-situ polymerization. GO and FGO were characterized by Fourier Transform Infrared Spectrometry (FTIR), X-ray Powder Diffractometer (XRD) and Transmission Electron Microscopy (TEM). The perpoties of epoxy resin/graphene nanocomposite were studied by FTIR, XRD, thermogravimetric analyzer (TGA), TEM, electrochemical impedance spectroscopy (EIS), contact angle and UV accelerated weathering test. Incorporation with 0.5 wt% FGO into hydrogenated DGEBA coating significantly enhanced the corrosion resistant which was attribute to well- dispersed of FGO act as barrier for corrosion factors. The second part of research, we synthesized two kind of GO/chromium complex hybrid materials. The hybrid materials were characterized by FTIR, XRD and TEM. Then we applied the hybrid materials for dye sensitized solar cell (DSSC) counter electrode. The properties of devices were analyzed by J-V curve, EQE and EIS. Results show that compared with the less ligand complex CrCl2, the GO/CrL3 hybrid material showing the better performance in DSSC device. The decive efficiency based on GO/CrL3 (1:1) counter electrode reaching 7.44 %, which was closing the Pt based counter electrode decive efficiency 8.88 %.
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43

Chen, Wei-Hong, and 陳韋宏. "Hydrothermal synthesis of titanium dioxide for the light scattering layer and Electrolyte doping with Graphene Oxide of dye-sensitized solar cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/rfgnnw.

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碩士<br>國立東華大學<br>材料科學與工程學系<br>106<br>In this study, by using hydrothermal method to synthesis titanium dioxide aggregation. The particle size was about 300 nanometer to 1 micrometer to achieve high scattering effect, and the morphology was similar with hydrangea. By mixing hydrangea TiO2 and P25-TiO2, makes more fitting with scattering electrode and the working electrode, so that efficiency can be improved.   Graphene Oxide can reduce the recombination of electrons in the electrolyte, we used freeze-drying method to get porous graphene oxide, and added to electrolyte, so that pores make the electrolyte more filling, increasing current transfer as well, enhancing the efficiency to dye-sensitized solar cells.
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44

LIN, JIA-CHIUN, and 林家群. "Mesoporous Carbon Nanofibers Prepared by Thermal Pyrolysis of Zinc-organic Frameworks as the Counter-electrode Catalysts for Dye-sensitized Solar Cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/c7275s.

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碩士<br>國立高雄應用科技大學<br>化學工程與材料工程系博碩士班<br>106<br>The zinc-organic framework (Zn-BTC fiber) was prepared by hydrothermal method. Carbon nanofibers (CNFs) were prepared by direct pyrolysis of Zn-organic framework fibers under a nitrogen atmosphere at a high temperature of 950C for 5 h. After pyrolysis, the carbon composite was treated with HNO3 (CNFs-acid), leading to an increase in the specific surface area. The small mesopores contributed to high surface area and the large mesopores speeded up the transport of electrolyte species. Moreover, this study used a simple sulfurization strategy to obtain the sulfur-doped CNFs (CNFs-S). The different carbon catalysts were coated on FTO (fluorine-doped tin oxide) electrode by electrophoretic deposition at ambient temperature as the counter electrodes for dye-sensitized solar cells (DSSCs). Surface morphology and microstructure results revealed that the precursors showed a nanofiber-like shape (diameter ≈ 800 nm, tube length ≈ 3-10 μm). The precusors after different treatments have a slight decrease in diameter and a rough surface. X-ray diffraction patterns displayed the characteristic peaks of znic oxide and carbon. The carbon materials contained large numbers of defects. Nitrogen adsorption/desorption isotherms showed the mesoporous nature of carbon nanofibers with high surface area (> 1300 m2 g-1). The cyclic voltammetry and electrochemical impedance measurements indicated that the CNFs-S electrode exhibited better catalytic performance than the CNFs, CNFs-acid, and Pt electrodes. After 1000 cyclic voltammetry tests, the anodic and cathodic peak currents remained almost unchanged. The counter electrode of CNFs-S also showed a stable performance towards I-/I3- redox couple. DSSC employing the CNFs-S counter electrode (CE) exhibited a high photovoltaic conversion efficiency of 10 %, which was greater than those obtained using Pt (9.34 %), CNFs (7.80 %), and CNFs-acid (8.01 %) CEs.
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45

Wan, Ting-Hao, and 萬庭豪. "Pt-decorated reduced graphene oxide counter electrode dye-sensitized solar cells: a comparison study of furnace and atmospheric pressure plasma jet calcination." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/6kbjs2.

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碩士<br>國立臺灣大學<br>應用力學研究所<br>105<br>We comparatively investigate dye-sensitized solar cells (DSSCs) with Pt-decorated reduced graphene oxides (rGOs) counter electrodes calcined by furnace and atmospheric-pressure plasma jet (APPJ). Pastes that contain chloroplatinic acid solution, rGOs, ethyl cellulose, and terpineol are first screen-printed onto fluorine-doped tin oxide (FTO) glass substrate and then calcined by furnace or nitrogen APPJ. The substrate temperature is set to 510 °C in both cases. Pt nanodots are well distributed on the rGO nanoflakes after furnace or APPJ calcination. Both rGO and Pt can enhance the catalytic effect for reducing I3− to I−.A nitrogen APPJ interacts vigorously with carbonaceous materials in the pastes to enhance DSSC efficiency with a shorter processing time. However, prolonged APPJ-calcination can damage/oxidize rGOs; therefore, for longer processing times, furnace-calcination in turn achieves better DSSC performance. These results agree well with those of electrochemical impedance spectroscopy (EIS) and Tafel experiments.
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46

CHOU, YU-RU, and 周育如. "Preparation of Graphene/ Macrocyclic Manganese Complex/ Poly (3,4-ethylenedioxythiophene) Composites and Its Application for the Counter Electrode of Dye-Sensitized Solar Cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/hn6966.

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碩士<br>輔仁大學<br>化學系<br>106<br>In recent years, dye-sensitized solar cells (DSSCs) exhibit with an exciting development especially in improving the energy conversion efficiency and reduce costs. As traditional platinum counter electrode is expensive, the commercialization of a low-cost DSSC is limited. Therefore, we are hoping to develop graphene-based cost-effective counter electrode materials to replace platinum. The studies of this thesis are divided into two parts: First, we used graphene and the macrocyclic manganese complex to develop a new composite material, which was applied to the counter electrode of DSSCs. In our study, various hybrid materials were made from graphene oxide and macrocyclic manganese complex with different ratios. The as-prepared hybrid materials were characterized by FTIR, XRD, XPS and TEM. As a result, macrocyclic manganese complex reacted with graphene oxide can effectively guiding the metal complex distributed uniformly on the surface of graphene. The properties of devices were analyzed by CV, IPCE, EIS and J-V curve. As a result, the counter electrode fabricated with the GO/Mn (1:10) hybrid material had a better redox behavior for I3- and exhibited the lowest impedance. Comparison with the same devices structure, the device efficiency based on GO/Mn (1:10) counter electrode reaching for 7.47 %, which is better than the Pt counter electrode with efficiency for 7.11 %. The results prove that using the materials of macrocyclic manganese complex hybrid with graphene could successfully apply for the counter electrodes of DSSCs. It is also the first case to form a composite material of a macrocyclic manganese complex with graphene and used to the counter electrodes of dye-sensitized solar cells. Second, the graphene/macrocyclic manganese complex was sintered at a different temperatures and added to poly (3,4-ethylenedioxythiophene) (PEDOT) to form a composite, which is applied to the counter electrode of the DSSCs. After high-temperature sintering, the manganese nanoparticles formed on the surface of reduced graphene oxide, which abbreviates as rGO/Mn. The rGO/Mn nanocomposite would increase the active sites for electrocatalyst of triiodide electrolyte and is expected to improve the efficiency of the PEDOT counter electrodes. The rGO/Mn materials were characterized by TEM, SEM, FTIR and TGA. As a result, under high temperature, the macrocyclic structure can be destruct, and the manganese nanoparticles deposited on the surface of rGO. Observation from SEM, the PEDOT/rGO/Mn materials have a continuous surface morphology. The surface roughness of the PEDOT materials was analysis by AFM. As a result, adding rGO material could improve the surface roughness of PEDOT. PEDOT composite material showed the uniform dispersion of manganese nanoparticle in PEDOT polymer matrix as observation of TEM images. The properties of devices were analyzed by CV, IPCE, EIS and J-V curve. As a result, the counter electrode fabricated with the PEDOT/rGO/Mn-300 material had a better redox behavior for I3-, with a more reversible redox behavior, and the lowest impedance. Comparison the various devices, the device efficiency based on PEDOT/rGO/Mn-300 counter electrode reaching for 7.85 %. This result confirms that the PEDOT/rGO/Mn-300 electrode can replace the Pt electrode of the DSSCs.
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47

WU, CHUN-HAN, and 吳俊翰. "1. PEDOT:PSS/Reduced Graphene Oxide/Macrocyclic Zinc Complex Composites Prepared by In-situ Emulsion Polymerization for Counter Electrodes of Dye-sensitized Solar Cells2. Functional Graphene Oxide/Polystyrene Nanocomposites for Encapsulation of Perovskite Solar Cells." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/f36tbt.

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碩士<br>輔仁大學<br>化學系<br>107<br>Dye-sensitized solar cells (DSSCs) and Perovskite solar cells (PSCs) have the advantages of simple process, high efficiency, and low cost. DSSCs are well developed, which exhibits with a more stable device performance in device efficiency. However, platinum counter electrode is relative expensive. It is one of the major issues for application of DSSCs. On the other hand, the developing of PSCs is growing rapidly with excellent power conversion efficiency. Due to the active layer of perovskite is moisture and oxygen sensitive, the stability of PSCs is still facing challenge for commercialization. Therefore, many researchers have invested in the study of stability and life of PSCs. High efficiency and thin film process PSCs have potentials for application in the future. In the first part, an in-situ emulsion polymerization was used to prepare poly (3,4-ethylenedioxythiophene): polystyrene sulfonate/reduced graphene oxide/macrocyclic zinc complex (PEDOT:PSS/rGO/macrocyclic Zn complex). To improve the dispersibility in PEDOT:PSS, GO/macrocyclic Zn complex hybrid materials were prepared by a freeze-drying method, and the hybrid materials were then annealed at 300 °C, 500 °C and 700 °C to obtain rGO/zinc nanoparticles (rGO/Zn) composite materials, which were used for preparation of PEDOT:PSS/rGO/rGO/Zn nanocomposites. Furthermore, we applied PEDOT:PSS/rGO/Zn nanocomposites to the counter electrodes of the DSSCs. The structure, thermal properties, and surface morphology of materials were identified by FT-IR, XRD, XPS, Raman, TGA, and SEM. The device performance of DSSCs for application of counter electrodes were evaluated by CV, JV Curve, EQE, and EIS analyses. The results showed that PEDOT:PSS/rGO/Zn nanocomposites were successfully applied to the counter electrodes of DSSCs, in which the device efficiency is comparable to platinum electrode, and the PEDOT:PSS/rGO/Zn-300℃ reaches the best device efficiency. In the second part, an in-situ emulsion polymerization was used to prepare polystyrene (PS) and functionalized graphene oxide (pv-GO) nanocomposites. Chemical bonding by using a vinyl-functionalized graphene (pv-GO) reacted with the vinyl group on styrene through in-situ emulsion polymerization was designed to improve the dispersion of pv-GO in PS. FT-IR, XRD, XPS, and Raman were used to identify the materials structure. TGA and DSC were used to observe the thermal properties of PS/pv-GO composites. TEM was used to identify morphologies of functional graphene oxides. Contact angle test (CA) was used to evaluate the hydrophobic properties of the composite films. In addition, PS/pv-GO nanocomposite coatings were applied for the encapsulation materials of perovskite solar cells. For example, the PS/pv-GO-2wt% nanocomposite has the best long tern stability for perovskite solar cells, which was evaluated under a stability test of 40% humidity in the atmosphere for 60 hours. As a result, the efficiency of the PS/pv-GO-2wt% encapsulated device is remain normalized 87%, which is 32% higher than unpackaged device.
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